Mechanism of tissue expansion in the early stage of the migration

The collective cell migration is observed in many biological processes such as wound healing, embryogenesis, and cancer metastasis. Despite extensive theoretical and experimental studies on collective cell motion, there is no unified mechanism to explain it. In this work, we experimentally report the collectively growing cell colonies in the sub-marginal region of a freely expanding cell monolayer. These colonies could be responsible for the highly aligned collective cell migration observed in front cell rows. Our results provide a basic framework to understand the physical mechanism responsible for collective cell migration in the freely expanding monolayer.

Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

This study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

Characteristics and moisture sources of the stable isotopes in precipitation in the monsoon marginal region of north-central China

The stable hydrogen and oxygen isotopes in precipitation (δD and δ18O, respectively) are important source signatures for understanding the hydrological cycle and paleoclimatic reconstruction. In this study, 32 precipitation samples were collected from April to October 2014 at the Luya Mountain summit, a representative site in the monsoon marginal area of north-central China. The isotopic signatures of precipitation exhibited strong seasonal variations ranging from -185.61‰ to -18.50‰ and -25.51‰ to -4.59‰ for δD and δ18O, respectively, which were relatively higher in August and lower in September. The local meteoric water line was δD=(7.95±0.16) δ18O+(15.79±1.77) (R2 = 0.988, N = 32, p < 0.001), which had a similar slope but higher intercept than that of the global meteoric water line, indicating that the precipitation in this area is mainly sourced from the ocean surface transported via monsoons. Additionally, the secondary evaporated water by continental recycled moisture was identified by the significantly higher deuterium excess value (16.09‰). Backward trajectories generated via the Hybrid Single-Particle Lagrangian Integrated Trajectory model indicated seasonal moisture transport changes in the studied monsoonal marginal region, in which the main moisture sources were the Westerly winds in April, the Pacific Ocean in July, and the Indian Ocean in September. Secondary evaporated water from the alpine ecosystem may also influence the local atmospheric water cycle throughout the year. Positive temperature-isotopic signature effect (δD and δ18O) was observed in the cold season (before mid-May); however, the precipitation amount effect was observed in the monsoon season from June to August, and both effects became vague across the entire period. These findings suggest that the stable isotope compositions of precipitation can be utilized to determine the moisture sources in the monsoon marginal region of north-central China and potentially be utilized to reconstruct the precipitation signals in this region.

Marginal and Internal Precision of Zirconia Four-Unit Fixed Partial Denture Frameworks Produced Using Four Milling Systems

Background: CAD/CAM systems enable the production of fixed partial dentures with small and reproducible internal and marginal gaps. Purpose: The purpose of this study was to evaluate the reproducibility of the marginal and internal adaptations of four-unit fixed partial denture frameworks produced using four CAD/CAM systems. Materials and Methods: Prepared dies of a master model that simulated the loss of the first left molar were measured. Fifteen frameworks were manufactured using four CAD/CAM systems (A–D). The internal fit was determined by the replica technique, and the marginal gap was determined by microscopy. ANOVA was carried out to detect significant differences, and the Bonferroni adjustment was performed. The global level of significance was set at 5%. Results: The mean gap size ranged from 84 to 132 µm (SD 43–71 µm). The CAD/CAM systems showed significant variance (p < 0.001), and system A (VHF) showed the smallest gaps. The smallest gaps for each system were in the molar part and in the marginal region of the frameworks (p < 0.001). Conclusions: The CAD/CAM systems showed significantly different gap sizes, particularly between premolars and molars and among the marginal, axial and occlusal regions. All of the systems are suitable for clinical application.

Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

This study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. A supragingival finish line is recommended for interim crown fabrication using an intraoral scanner.

Prologue

This chapter provides an overview of how the events in Feng County, Jiangsu Province, reveal a world of continuous conflict that goes well beyond anything even hinted at in previous studies of the Cultural Revolution. Despite its remote location, in a poor and marginal region at the intersection of three provincial borders, the county was deeply disrupted by factional divisions that formed in 1967 and continued to shape local politics until shortly after the death of Mao Zedong a decade later. Each shift in national politics emanating from Beijing during the 1970s had a major impact on the balance of factional forces in the county, although the impact was often very much at odds with the intentions of national leaders. The county's history also reveals in remarkable detail the deep involvement of China's armed forces in the definition and perpetuation of county-level factionalism. Military intervention in Feng County did serve to define the lines of factional conflict, but in ways very different from previous understandings.

MARGINAL REGION MATHEMATICS TEACHERS’ PERCEPTION OF USING ICT MEDIA

The article presents a marginal region of mathematics teachers' perception of ICT as learning media and the type of ICT media used in mathematics classroom. A survey was designed including two domains: the usability and the importance of ICT. A questionnaire was administered to 84 mathematics teachers in marginal regions. The respondents were chosen conveniently based on their accessibility and availability. About 50% of marginal region mathematics teachers do not use ICT in teaching. The most common media used is Microsoft Office software to present teaching materials from internet or digital sources. Using Rasch model, the data show that mathematics teachers' perception of the usage and importance of ICT as a media of mathematics learning can be categorized as 'medium' level. Mathematics teachers in the marginal regions consider ICT as mathematics learning media to be fairly important.

Lithological variations and drainage evolution in a marginal region: A case study from Chandrapur block of the Pranhita-Godavari Basin, Central India.

Field mapping and interpretation of sedimentary structures in Gojoli region of Chandrapur block along the eastern margin of the Pranhita-Godavari valley suggests westward flowing channels during the Neoproterozoic. Present channels in this part of Chandrapur block are south/ southeast flowing and possess clear imprints of the basin-margin faults and lineaments. Drainage parameters in its Neoproterozoic stratigraphic sequence suggest impervious substrates probably due to high degree of consolidation and filling of rock-fractures by hydrothermal solution activities. However, the same for the Gondwana’s friable sandstone (towards western region) and Archaean gneisses (in the eastern part) has been observed consistent probably due to its porous nature and development of thick weathering profile. The affiliation of drainage with tectonism is therefore, from Neoproterozoic to Cenozoic era within contrasting lithology, was out of synchronization intermittently.

Description of a new species of Kermicus Newstead (Hemiptera: Coccomorpha: Pseudococcidae) from bamboo in southeast China

A new species, Kermicus huizhouensis Wu & Huang sp. n. (Hemiptera: Coccomorpha: Pseudococcidae), is described and illustrated based on the adult female, second instar female and first-instar nymph. It was collected at Qianfeng village, Huiyang District, Huizhou City, Guangdong Province, P. R. China, inside the stem of bamboo Bambusa rigida (Poaceae) and attended by the ant Tetraponera binghami (Forel) (Hymenoptera: Formicidae). It differs from K. wroughtoni Newstead, 1897 by the adult female lacking multilocular disc pores in the marginal region of the venter, and both the adult female and first-instar nymph having the anal ring bearing 16–20 setae. Keys to genera of legless mealybugs on bamboo based on adult females, and the immature stages of Kermicus, are provided.

A landsystems approach to understanding the evolution of ice-cored topography and distribution of retrogressive thaw slumps, western Canadian Arctic

&lt;p&gt;The landscape of the Tuktoyaktuk Coastlands, western Canadian Arctic is dominated by glacial and geocryological processes that have modified, imprinted and sculpted the surface, depositing surficial materials upon underlying bedrock. Climate warming continues in this region at a rate that is twice the global average, and retrogressive thaw slump (RTS) activity is increasing. Recently, RTS distribution was associated with glacial limits reached by the Laurentide Ice Sheet and corresponding morainal deposits, but RTS are common in other local terrain units. In this glacial-marginal region, permafrost existed pre-glacially, and non-glacial geomorphic processes occurred throughout the Late Quaternary. Superimposed on these conditions are the effects of thermokarst during the Holocene climatic optimum, followed by a period of cooling. Collectively, these processes and associated forms and deposits have contributed variously to preservation, development, or degradation of permafrost and ground ice. The multifaceted Late Quaternary history in this region has impeded understanding of the distributions of ice-cored topography and RTS. For example, rather than glaciogenic ice, the long reigning regional model for ice-cored topography is according to post-glacial development of intrasedimental segregation-intrusion ice. Toward better understanding the evolution of the whole landscape and the distribution of climate-sensitive terrain, we use a landsystems approach as a means to understand how the ice-cored topography developed where RTS form, through analysing the cryostratigraphy. To this end, we identify 6 RTS representing a suite of ice-cored topographic settings, including: (i) preserved basal glacial ice facies within clayey diamict that has been thrusted and folded by glacial push representing morainal deposits of the Sitidgi Stade; (ii) ice contact outwash sediments associated with the Sitidgi Stade, overlying a thermo-erosional contact with underlying basal glacial icy diamict of the Toker Point Stade; (iii) deformed basal glacial ice, eroded down by meltwater-deposited outwash sands some time between the Toker Point and Sitidgi Stades (could be ca. 12.9 kyr BP); (iv) massive, undeformed segregation-intrusion basal ice, likely formed subglacially by freezing of intrasedimental water in pre-existing Pleistocene sands into the base of the glacier, overlain by glacial diamicton; &amp;#160;(v) deformed basal ice facies of intermediate Toker Point &amp;#8211; Sitidgi Stades, with an upper layer that may be supra-glacial melt-out till into which segregated ice formed; and (vi) segregation ice that formed as permafrost aggraded into glaciolacustrine clays deposited in proglacial or glacially dammed basins, that was subsequently eroded down by glaciofluvial outwash (Sitidgi Stade). To summarize, the distribution of RTS reflects primarily the distribution of icy basal glacial diamict preserved in moraines, but also basal ice and icy basal diamict that are preserved beneath glaciofluvial deposits, segregation ice in glaciolacustrine deposits, and massive segregation-intrusion ice in Pleistocene sands beneath a till plain.&lt;/p&gt;